Today's telephony users generally have at least one wireline-based telephone terminal receiving services through the public switched telephone network (PSTN) and a mobile terminal receiving services through a cellular network. These wireline and mobile terminals are incompatible, and thus incapable of facilitating communications over both cellular and public switched networks. As such, telephony users must juggle multiple telephone terminals, using one terminal to make and receive calls via the cellular network, and another to make and receive calls via the PSTN. In addition to the user having to keep track of multiple terminals, incoming calls are generally free through the service providers of the PSTN, while cellular service providers charge for such incoming calls.
To address these issues, communication technology is advancing to a point where specially configured mobile terminals can communicate via a cellular-based wireless network, as well as the PSTN or a data access network through a terminal adaptor. For clarity, the mobile terminal, which is capable of operating in both modes, is referred to as a dual-mode terminal. The terminal adaptor may be coupled to the PSTN or data access network and communicates wirelessly with the dual-mode terminal using local wireless access technology, such as traditional analog and digital cordless technologies, 802.11 wireless local area network technologies, and Bluetooth technology. Notably, the dual-mode terminal may be permanently or temporarily associated with one address, such as a directory number, for cellular access, and another for PSTN or data access.
Through one of the connections to the PSTN or data access network, the terminal adaptor may have a data interface through which it can communicate with a service node, which may control the routing of incoming calls directed to the mobile terminal through the wireless network, PSTN, or data access network. The terminal adaptor may determine when the dual-mode terminal is within a zone in which communication via the local wireless access technology is possible, and provide information to the service node bearing on whether the mobile terminal is within or outside of the zone. In other embodiments, the dual-mode terminal may determine when communications with the terminal adaptor are possible and provide alerts through the wireless network or via the terminal adaptor. For example, the service node may take this information and direct incoming calls to the PSTN directory number associated with the terminal adaptor when the mobile terminal is within the zone, and direct calls to the directory number associated with the wireless network when the mobile terminal is outside of the zone.
For additional information on dual-mode terminals and related communication systems, attention is directed to co-assigned U.S. patent application Ser. No. 10/409,280, entitled INTEGRATED WIRELINE AND WIRELESS SERVICE, filed Apr. 8, 2003; Ser. No. 10/409,290, entitled CALL TRANSFER FOR AN INTEGRATED WIRELINE AND WIRELESS SERVICE, filed Apr. 8, 2003; Ser. No. 10/626,677, entitled INTEGRATED WIRELINE AND WIRELESS SERVICE USING A COMMON DIRECTORY NUMBER, filed Jul. 24, 2003; Ser. No. 60/472,277, entitled WLAN CALL HANDOFF TO WIRELESS USING DYNAMICALLY ASSIGNED TEMPORARY NUMBER, filed May 21, 2003; Ser. No. 60/472,152, entitled HANDOFF FROM CELLULAR NETWORK TO WLAN NETWORK, filed May 21, 2003; Ser. No. 10/693,540, entitled CALL TRANSFER FOR AN INTEGRATED WIRELINE AND WIRELESS SERVICE USING A TEMPORARY DIRECTORY NUMBER, filed Oct. 24, 2003; and Ser. No. 10/693,539, entitled CALL TRANSFER FOR AN INTEGRATED WIRELINE AND WIRELESS SERVICE USING A TEMPORARY DIRECTORY NUMBER, filed Oct. 24, 2003.
Communication systems supporting the above described dual-mode capability have yet to accommodate short message service (SMS) and multimedia message service (MMS) technologies where short text or multimedia files are delivered between mobile terminals. In a dual-mode system as described above, there is no way for the SMS or MMS messages to be sent from or delivered to the dual-mode terminal when it is being supported solely by the terminal adaptor. The SMS or MMS messaging is only supported when the wireless network supports the dual-mode terminal. As such, there is a need for a technique for fully supporting SMS and MMS messaging for dual-mode terminals, regardless of whether the dual-mode terminal is supported by the terminal adaptor or the wireless network.